Dress chicken breasts with olive oil, lime zest and juice, salt and pepper. On an outdoor grill or grill pan, cook chicken over medium-high heat until cooked through. Slice on a bias and reserve.

In a shallow pot over medium-high heat, add quinoa and 1 1/2 cups of water. Bring to a bubble, lower heat to a simmer and cover. Cook for 15 minutes. Add cilantro, lime zest and juice, and season with salt and pepper while quinoa is still warm. Keep covered until ready to serve.

While the quinoa is cooking, heat oil in a large skillet over medium-high heat. Add in sweet potatoes and cook for about 3-5 minutes, or until just about brown. Add in taco seasoning, red onion, and chicken stock and cook, stirring or tossing occasionally, until the potatoes are tender, about 8-10 minutes. Add in black beans; stir to combine and warm through, about 2 minutes.